Autologous Epstein-Barr virus (EBV)-specific cytotoxic T cells for the treatment of persistent active EBV infection

Chronic active Epstein-Barr virus (CAEBV) infection syndrome is a heterogeneous EBV-related disorder characterized by chronic fatigue, fever, lymphadenopathy, and/or hepatosplenomegaly, associated with abnormal patterns of antibody to EBV. CAEBV can range from disabling mild/moderate forms to rapidly lethal disorders. Even patients with mild/moderate disease frequently suffer adverse effects from long-term anti-inflammatory agents and have a quality of life that progressively deteriorates. It is still unknown why these individuals are unable to produce an effective immune response to control EBV, and no effective treatment is currently available. Since ex vivo-expanded EBV-specific cytotoxic T lymphocytes (EBV-CTLs) can safely restore EBV-specific cellular immune responses in immunodeficient patients, we assessed the possibility that adoptive immunotherapy might also effectively treat CAEBV infection. Following stimulation with irradiated EBV-transformed lymphoblastoid cell lines (LCLs), EBV-CTLs were successfully generated from 8 of 8 patients with the mild/moderate form of CAEBV infection. These CTLs were predominantly CD3⁺ CD8⁺ cells and produced specific killing of the autologous LCLs. There were 5 patients with 1- to 12-year histories of disease who were treated with 1 to 4 injections of EBV-CTLs. Following infusion, there was resolution of fatigue and malaise, disappearance of fever, and regression of lymphadenopathy and splenomegaly. The pattern and titers of anti-EBV antibodies also normalized. No toxicity was observed. There were 4 patients who did not show any relapse of disease within 6 to 36 months follow-up; one patient had recurrence of fatigue and myalgia one year after CTL infusion. We suggest that adoptive immunotherapy with autologous EBV-CTLs may represent a safe and feasible alternative treatment for patients affected with mild/moderate CAEBV infection and that this approach should be evaluated in the more severe forms of the disease.